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y E. J. BLAKE ELECTRICAL REGULATING APPARATUS Filed Jan. 3, 1923 3 Sheets-Sheet 1 INVENTOR a, MA.

192 May 31 7 E. J. BLAKE ELECTRICAL REGULATING APPARATUS Filed Jan. 3. 1923 3 Sheets-Sheet 2 May 31, 1927. 1,630,823

v E. J. BLAKE ELECTRICAL RBGULATING APPARATUS Filed Jan. 3, 1923 3 Sheets-Sheet 3 4 INVENTOR gig w a. 6

BY A421 ATTORNEYS Patented May 31, 1927.

UNITED STATES ELI J. BLAKE, F BUFFALO, NEW YORK,

GOULD CAR LIGHTING CORPORATION, MARYLAND.

assrciiomny MESNE ASSIGNMENTS, '1'0 OF new YORK, M Y.-, A CORPORATION or ELECTRICAL REGULATIIil'G APPARATUS.

Application filed Januar e, 1923. Serial Nb. 610,419.

My invention relates tO lXIIPIOVBIDQIItS in electrical regulating apparatus and more particularly to regulating apparatus for electrical generators driven at variable speed as from the axle of a railway car for supplying a storage battery and electric lights or other energyconsuming devices. The main object of the invention is to provide an arrangement which is not only simple and eflici ent in operation but also one which is reliable and not likely to get out of order. Further and more specific ob jects, features and advantages will. more clearly appear from the detail description given below taken in connection with the paratus adapted forcarrying out the inven tions'.

accompanying drawings which form a part of this specification.

In the drawings, Fig. 1 is a face view of a panel on which is located regulating aption in a preferred form thereof. Fig. 2 is a side view of the same. Fig. 3 1s a view siinilar to Fig. l but largely diagrammatic in order to show thevarious circuit connec F ig.4 isa plan view of the generatoriregulator carbon piles of .Figs 1, 2 and 3- i of variable resistance shown in F 1g. {1.

30 ei'ator driven-at variable speed as from the.

axle. of a railway car and-12 a shunt field therefor. 3 and fihrepresen t pole wpieces of an electronagnet pivoted between which at ;5 is an armature 6 hav ng a p n 7 adapted; p u H the generator leads fro to bear against the lower end of a lever 8 pivoted at 9.- the. upper end of which ace. tuates a cross piece 10 andpluiigers lland j '12 hearing against one end respectively of icarbon piles l3and let. A spring 126' (shown in 1) tends to draw the arma-I ture 6 out of alignment with thepole pieces,

and acts throughthe lever 8 to compress-the carbon pile. 15 and 16 represent pole pieces:

'of an. electro-magnet between which. pole pieces is pivoted at 17, armature 18 having a pin 19 hearing against the lower end of; a lever 20 pivoted at 21, the upper end of wrhich lever is adapted to operate a cross piece22 and plungers 23 and 24 operating on the other end of carbon piles 13 and 14 respectively. A spring 130 (shown in Figs. 1 and 2) tends to retract the armature and compress the piles.

25 representsan armature pivoted at 26 of'ari electro-magnet.

Fig. 5 is an end view' partly in section Q between the pole pieces 4 and 16 having pivoted thereto at 27, a link 28 pivoted at its lower end to i y A spring 129 (shown'in Fig." retract the armature and open 32 represents a storage battery 'a'ncl'j31. 1) tends to the switch. adapted to devices 33 when the generator is"not running or. is not'running at s'uflicientspeed to supply the necessary voltage for the same. 34 represents another variable resistance carbon pile in series betweenthe storage battery 32 and lamps 33, and adapted to'b actuated by plunger '35 operated by lever 36'pive-ted'at its upper end to the frame at adapted to V be charged by'thegenerator I. and to supply l'a'rnps or other work circuit Y a switch member 2 9'adapte d" to close the. circuit between fixed contacts 37 and carrying at itslower end a roller 38 be actuated by ac'am,39 fix'ed' .orran armature 4 0, pivoted at itslcenterto the'j frame between pole pieces 41., and

A p i 61 (sho .in liigl 1) tends toretra'ct the almfi ll fe 'an'd' compress the pile adapted to connect Y the switch, being .;ac'tuated 'by an arm 43 represents a switch electrical contacts Mi and grani natic showingi'the (smite-b se pin rifi f ug caramel: rea .b fd ejp s thence: thiioiigh c'ond iictori 56 did bind:

the battery' 32 and conductor 59 't0 the I t-tractsco're 46, the switch: -meiiiber 43 is pulled :u pto electrically 'cor'i'ne As shown 'm Fig i i the froin' nji hq p'qs -iv Po e or 52and an electro'-' ing post '57, fthenc e. thr ligi c'o 'i'du'ctor 58 to lamps 33. From the. 0pposite terminal 'of the-[lamp or work, circuit, the maincurrent .pasiesthrough conductor 60 and binding post 61, .thence' through the carbon pile 34 and conductor 62, binding'po'st 63, thence through conductor 64,- binding post" through switch member' or contact piece 66 and conductors 67 and '68, bindingpost 69, through switch contact 30, switch 29, switch contact 31 to binding post 70, thence through main fuse 71 and conductor 72 to the negative side of the generator 1. The

volt'a 102, car

main current from the battery returns through cond'u ctorf 73, binding post 7 1, thence" through conductor 75, binding post 76, thence through conductor 77 and electro-inagnetcoil :7 8 on:1the. magnet adpxcent polepiece 3, thence through conductor 79, binding post- 80 and then through conductors 81 and 68 and back to the negative terminal of the generator. 82 represents an electro-niagneticcoil on the Iriagnet ad a cent pole piece '15 which electro-rnagnetic coil 82 niay"be' connected in the lamp 611'- cuitor b'rahchfby'swingihg contact 66 away front contact 85 and causing it to connect contactsf65fand 8lf1IThefcurrent from the mmps th passes fjrornjcontact 65 to conta'ct 811, t hen through conductor 86, coil 82, conductor BY'to th e' bindin post 85 and thence, through'iconductors' and Y 08' back to'the "eii ftiVe'side the'gencrhtor.

Tllecai bon pil'e 34fiitlif its operative parts seryes a'sja maintain submanually constant yolta ge fon the lamps' resp t v Qt h'itue eaime 9 t b tcQty? .1' For? thi n 56 ,ls t eg c coils '88 iivliich effigfigize the electromag'net oiqelatirig' thear n a ti1re-40, are conneta;-ii;;-sr ie with .q another and also acr os' sf tlie llniie s v f t' df tlitqliy. i..j b,3 b p le ils a mii rsief e be ee 1. .fel b i l b fify: ha lt II PS j min a .1 J'g' stat ytendeh'c o a' tlecrease in volt age t ac ossTtl e lamps causes" an opposite ffe Thparbgi p es 1 3 ";nttl ljl are connected in series with'one; another and inseries with h h m ,fi ldfl c 16 g iQ i'Q C- the circuit folloxy s fforn the positive side of the g e'nerato'u 'through shunt 'field t1 g-,.1 l it. 99 thro he ondurt 1 binding 0st thence through conductor tom-pile the ce t mug wmnductjor- 103, and 'ca 1 'bon j pile. 13, thence through conductor 104,; fuse 1105, conductor. 106,rnain'vflijl and conductor 7 2 to the opposite side of the generator. 107'repre-" m. th ei s there sstliefbatteii' theri the I maintainsubstantially constant batterv cur ole pieces 11 and scnts a voltage coil connected across the generator' and battery through a ballast resistance108, the circuit being as follows-from the positive side of the generator through conductor 50; binding post 51, conductor 52, coil 53, conductor 5 binding post 55, conductor 108, binding post 109, electromagnetic coil 107,'-bintlin'g post 110, conductor 111 binding post 112 ballast resistance 108,

binding post 113, conductor 11%, back to conductor 72 on the negative side of the generator. The positive connection for the voltage coil 10? is made at the binding post 55, adjacent to p the battery connetztion rather than at binding post 51, adjacent to the generator in ordcnthat the voltage coil may control in accordance with the output voltcontacts 30 and'31'and thus close thecircuit from the generator to the st oragebat tery and lanips. If as the speed of the generator increases thecurrent suppliedby the generator sag-111d tend to become greater than-that. (les1red,'t he'strengtli of coil 53 will be such 1's to attrac't'thearinature 18 and th us move pin'19' away' from lever 20 and sorelitav'ethe pressure" exerted thereby ighbhandends' of carbon" piles 13 and .lflfas viewlecl' in .3 and thus weaken thefield of tlte'generatoriand so maintain the voltage of the generatorfat such a value as' to"n1ai1itain'substzintially constant current td an increase in outputof the ge' ''ratbr': f its desired to rent irrespective oftheuniount ot the current taken by tlle'lan'qp' or ork 'circuit tlien i turning from thelanio'spass'es through elec- 82 which is wound on the i-magn t 'i magnetic frame sons to oppose coil 53 so tliatthe net result is' a regulationof the gen j eratorfto mainta n substantially constant.

13 and 14 asvieived in Fig. so regulating thc fiel'd strength the generator as to mmmm voltage thereof sr'iljstantially constant This ,tends to produce a gradual tapering off of the battery current as its bacl; 54

: and 4 and is connected in the battery branch and therefore, is responsive to decreases in the battery circuit. It is wound to oppose the electro-magnetic coil 107 whereby a decrease in the battery current through electromagnet 78 increases the effective strength of magnet coil 107 on the armature 6 and so causes the same to regulate the generator to maintain a gradually decreasing voltage output which causes a more rapid tapering off of the battery charging current at this stage.

WVhen the generator is not running or is running below critical speed and the main switch 29 is open and the storage battery 32 is supplying the lamps 33, the solenoid 47 acts upon core 46 to close switch 43 to connect contacts 44 and 45, thus placing a shunt circuit around the carbon pile 34 through conductor 98, the switch 43 and conductor 62, in order that the voltage drop between the battery 32 and lamp circuit 33 maybe reduced to a minimum. This is effected through the actioniof the main switch. One side of the solenoid 47 is-connected to contact 69 of the main switch-through conductor 115, conductor, 116,"binding post 74', conductor 75, binding post 76, conductor 77,

coil 7 8, conductor 7 9, binding post 80, conconductor ll4g' fus'e 71 and binding post 70.

\Vhen the main switch29 is open some current will pass'from' the battery back through the generator and't hrough coil 47"an d thus 1 energizesolenoid 47- and cause it to close switch 43 and thus shunt out the carbon-pile variable -resistance 34. When the main switch 29 is closed the-solenoid 47 is substantially short-circuited sothat the switch 43 is opened thereby placing the carbon pile 34 in series between thebattery and lamps. when certain typesof' storage batteries are used as for example, the sowalled'Edison battery, it may be desirable to place a further ballast resistance in series with the voltage regulating coil 107 and for this purpose an additional resistance 118 is provided con nected between binding posts 112 and 119. When it is desired to include this resistance in series with the ballast resistance 108, the conductor 120, one end of which is connected to the ballast resistance 108, is switched from binding post 112 to binding post 119.

As shown in Figs. 1 and 2 the main switch comprises leaf spring contacts 30 and 31 suitably secured to base piece 164 of insulating material which in turn is secured to the base panel 121. These contacts are beveled at their outer end and switch member 29 is bent to conform therewith and secured to a member 122 pivoted at its inner end by a knife edge member 165 bearing on the base piece 164 and adapted to be pulled upwardly by the link 28 attached to the armature 25 when the armature is attracted by its magnet. A spring 123 tends to maintain the link in position on the pin 124 on member 122 and pin 27 on the armature, and to hold the knife edge 165 against its seat.

The electro-magnet coils 78, 107, 53 and 82 areshown as mounted on the magnetic frame 125 secured to the base plate 121 by screws 126. The respective pole pieces 3, 4, 16 and 15 extend outwardly and co-axially from the respective electro-magnetic coils as shown in Figs. 1 and 2 so as to provide ample space for the armatures 6, 25 and 18 to swing therebetween, these armatures being pivoted on pivots carried by the frame 125. The outer ends of each are held'in' place by non-magnetic frame piece 127 extending across the front of the magnets. Armatures 6, 25 and 18 are normally swung away and out of line with their respective pole pieces by springs 128, 129' and 130 respectively, the upper ends of whichspring's are held n place by hooks 131, adjustably screwed into a frame plate 132, carried by posts 133 supported on a frame piece'134, secured to the' frame 125 by means of screws 135.

The lower ends of the springs 128, 129, and 130 are'connect'ed with links 154, 155 and 156, the lower ends of which'are pivotally connected with pins157, 158.and159 respectively, whichpins arerigid with the arma'tures 6, 25 and 18 respectively and extend up through holes 160, 161 and 162 respec tively in the outer frame plate .127. ;The springsi128, 129 and'130, therefore, normally .pull the immaturesv away from-and out of "line' with their respective pole pieces until the pins 157, 158 and 159 engage, the edges of the openings' 160, 161 and 162 re may operate upon the carbon piles 13 and The carbon piles 13 and 14 are contained in insulating cylinders 136 and 137 respec tively, which cylinders are closed by cap pieces 138 (see aisoFig. 4). 'In practice I prefer-to make the cylinders of steel tubes coated with vitreous insulating enamel. The

plu-ngers 11 12, 23 and 2-1 are adapted to slide through these cap plates and operate. on theends of the carbon piles: respectively through electrically conducting heads 139 attached to the inner ends thereof. The plungers 11 and 12 are connected together by the member 10, the ends of which fit in slots in nuts 140 secured on the plungers 11 and 12 respectively, and the cross-connecting member is provided with two buttons 141 against which the upper end of the lever 8 is adapted to bear, the upper end of lever 8 being relatively wide for this purpose. The plungers 23-.and 2 1 are opera- Lively connected together by a lever member 22 by reason ofthe ends of the member 22 being forked and bearing against pms 1 11 extending through the members 23 and 2-1 respectively. The member 22 is held to bear against the pins 141 by means of nuts 142 clamping bands 151" secured to each. otherand to the spacing blocks 149 at their centers by tubular rivets 166, and secured to each other at their ends by rivets 152. Lea-f springs 14?, 148 securediby screws 150- to the spacing blocks 149 serve to retam't-he cap pieces 138 in the ends of-the cylinders;

The parts shownin Fig. i l-thusconstitute= an assembled-unit whichis'removable from: the regulator for renewahor maintenance; Enlarged heads on the: Iowferrendsofnt-he rivets 152' serve as 'feeti-for -the assembled unit and rest on' bosses -forrned onthe frame member 134..- Studs: 153 projecting upward from the frame member throughthe-f tubular rivets 166 serve todocate'theassembled" unit, and wing'n'u'ts 167 screwed on the studs retain it in place." .I

The pole pieces 3. 4, 16 and'15 are cut awa as shown at 154 to accommodate the ends or the armaturesand permit the armatures-t-o swing about their pivots between thepole-pieces. The armaturesfi and 18 are provided with copper damping bands am order to damp out oscillations of the a-rmatures as far as practicable.

The ballast resistances 90 and 108' are tubular enameled resiSt-anceunits. At the right hand end in Fig. 1 they abut against a bracket 157 which is provided with bosses to' locate them. At the-left hand end they abut against suitably formed heads on plungers 168 which are forced inward to retain the resistance units by COIDPIBSSIOD' springs 158. The plungers 168 slide in openings formed in the bracket 169 which is attached to the base plate 121.

T he lamp regulator carbon pile 3% is supported on suitable insulating bars 159 and is provided with a fixed adjustable abutment t will benoted that the magnet coils 78, 10?, 53 and 82 are all wound on separate legs of the; magnetic-structure whereby the coils are similar in diameter and the arrangement isbetter adapted to act upon the torsion armatures pivoted between the respective pole pieces W hen the current coil 53 is acting to regulate the carbon piles 13 andld; by varying the; pressure through the plungers 23 and 24; the opposite ends of the piles-remain. substantially stationary. due to the liactthat-the spring 128 holdsthe armature 6 in its oli'-position, the voltage being insufficient to cause it to overcome the tensionofj spring.128'. Likewise during the periodrwhen the:voltage coil 107 is acting.

to. regulate the-carbon. piles 13 and. 1.4 through-,t-he plungers- 11%and12, the opposite ends Qfr'tb6-PikS 13 and 1 1 at plungers 23 and- 24;: remain substantially stationary.

'Thje tubes fiii. and 137 together with the straps 15110111} suitable supporting. means for the carboripiles-ldand l k which are removable therewith by merely unscrewing the wingnuts 167.. .These carbon piles are removable from I the, rest; of the parts without any disconnection item the levers '8 and since the Ieversare not connected with the piles .orthe plungers operating the same except by hearing against the plungers or the partswonnecting the plungers. That is. each: of the levers hasione end bearingon the plunge'rsbut isotherwise disconnected and free therefrom so that these carbon piles with their-supporting -means 'may be removed. withoutany disconnection from the piles or said. flevers: Likewise thelevers 8 and 20 are easily removed fromv the electro magnets and their armatuues because the levers are not positively connected therewith but-merely have-a bearing engagement with the operating pins on the a-rmatures, the armature pins being maintained in engagement withthe levers by the springs 128, etc. The springs 145 and 146 act to press the cross members 10'and 22. with the plunger-s away from the piles and toward the levers respectively to maintain the same in engagement with the upper ends of the levers S and 21 respectively. The lever 8' acts against the spaced apart bearing points 141 on cross member 10 and any unequal expansion between the piles l3 and 14 is-taken care of by the oscillation of the cross member 22 at the opposite end which has pivotal connection with the plungers. 23 and24 and only one bearing point against the lever 20.- When the system is being'started up the main switch 29 is open but when the-voltage applied to the voltage coil 107 reaches a critical value, it acts upon the armature 25 to cause the main switch to beclosed whereupon current. is supplied through the coil 53 in a direction to aid coil 107:acting on the armature 25 to maintain the main switch 29 closed. \Vhen the, voltage of the generator drops below the value necessary to chargethe battery or supply the lamps due to a decrease in the, speed vof the generator, then current ---i:rom-v the; battery will flow backthrough coil 53and through the, generator in the opposite=directionzand so decreasethe magnetic force'acting. on armature 25 as to, promptly openthe main switch. 1 By this arrangement itgwill beiseen that the main switch is operated bythesame coils which areiised for controlling; the carbon piles in series withthe generator Y When the armaturefi is held against its stop [by the spring; 128,; it .will reqmrefa certain potential applied to;,coihl()'{ to operate the armature to ,act onthegcarbon piles 13 and 14h The swingi of thega'rmature is .so arranged that afte the armature has started to swing toward. 1 .the ,pole ;p1ec es under such action of coil 107,-,a5slightlyless pot ial will 1-. b q d: 9 iiirthe vm re .the armature 6; in dine-with; -its pol e, pieces.

t it w r qu i-a-I difi rencez t e n three; or; four; voltsgto ffi stgstart thmarmature ;;6 over-, the. potential maintained throughout the remainder, ;o f;-,.the stroke although throughout substantially: the ,whole of the stroke, the potential act-uallyrequired to move the armature remains-substantially constant; this, being accomplished by, j'properly cosordinating the eifect-. f,spring-.128 with. the effect of the .electro-magnet on. the armature 6, at its different positionsand the t=ef anydb i -P. .ne., 1f c rb n r f that asl tu ning mcn app d to the armature,increases asjt approaches the, line of the zpol e pieces -withgaz giyen potential, the counter efi'ect of" the;..spring 128 similarly increases, and 1 this ,with 9 any material vincrease in ,back, pressure of the carbon pile, permits the. constant potential required to. maintain the armature 6 in any position throughout the mostiof, its movement. \Vith this effect it may beunnecessary to use the coil 78.

Altliough Lhave describedmy.improvements in great det ail and with respect to a preferred form thereof, I.. do.not desire to be limited to such details or form since many changes and modifications may be made and the invention embodied in widely different forms Without departing from the spirit and scope. thereof in its broader aspect.

' \Vhat I claim as new and desireto secure by Letters Patent, is:

1. In an apparatus of the class described the combinationof a compressible variable resistance, a magnet having two pole pieces, an armature therefor pivotally mounted between said poiepieces, means whereby said armature acts to vary said resistance, a current coil energizing said magnet to cause the armature to increase said resistance, and another current coil acting on said magnet to oppose theaction of'said, first coil, said coils being wound on separate legs of said magnet.- v

- 2. In. anapparatus of the class described the combination of a compressible variable resistance forregulating the voltage of 'a generator, amagnet having twopole pieces, an armature therefor pivotally mounted between said pole pieces, means. whereby said armature acts to vary said resistance, -and 'awcurrent coil and aivoltage, ooil acting on said magnet to control .said armature to'vary saidireslstance, said -coils; b eing..wound on separate.ilegs-of-saidmagnet;:n-r: 3; :Apparatus -of :the class descr'bed-having in -combination a carbon pile; a plunger operating on! one endnoflthe pile, a- 1 lever havin (one; end. bearing ,:on said plunger, .1 but'zotherwiseinot connected and; free therefrom, an electr'omag'netg and armature,-'sa1d 4 armature having a r: part=;; =-b'earing,-.= against saidi :lever but otherwisedisconnected 'and free therefrom-,1- and: resilient 2 means operat- 5 ingto: presssaid armatuiepart against said lever; and'lsaid deven againstrsaid :plunger. 4. Apparatus of; the-class described havingin combination =2; plurality -0fi carbon piles, plungers operating ion opposite ends of; eachi of said piles,- :a member connecting the; plungers at one .end, a member" connecting the-plungersat the othefi end, two levers operating onsaid members respectively and having abearing engagement therewith but being. OthGIfWiSQsE not -.connected therewith.

electro-magnets v; having war-matures? with parts bearings against said z'levers respectively but being otherwise disengagedtherewith, and resilient means acting to: maintain :sai'dkarmature-iparts inf engagement: with said levers? and said levels inengagement with said anembers.

I 5. Apparatusofitheclass described having in combination a plurality of carbon piles, plungers, operating on. opposite. ends of each oi said.piles, a member connecting the plungers atone end, amembe r connecting theplungers at the other end, two levers operating on said members-.respectively and having a bearing engagement therewith but being otherwise not connected therewith, electro-magnets having armatures w th parts bearing against said levers respectively but being otherwise disengaged therewith, and resilient means acting to maintain said armature parts in eng gement with said levers and said levers in engagement with said members, and resilient means pressing said members and plungers away from said piles and toward said levers re spectively.

6. An apparatus of the class described having in combination two carbon piles, a plunger operating on each end of each prle, means connecting the plunger-s at oneend, a lever having spaced apart bearing points on said means to operate said plungers simultaneously, elect-ro-magnetic means controlling said lever, an equalizing member having a pivotal connection with each of the plungersat the opposite end, a lever hav ng a single bearing point on saithequahzing member ,to operate said last mentioned plungers, and electro-magnetlc means controlling the operation of said-last mentioned lever.

7. An apparatus of the class described having in combination two carbon. prles plungers operating on each end of each pile, means connecting the plungers-at .one end, a lever having spaced apartbearing points on said means'to operate said plungers-simnltaneously, electro-mag-netic means controlling said lever, an equalizing member having a pivotal connection with each of the plungers at the opposite end, a lever hav ng a single bearingpoint on said equalizing member to operate said last mentioned plungers, and electro-magneticlmeans controlling the operation of said last-mentioned lever, and 'resilient means pressing the plungers and. connecting means and equalizing lever away from the pilewand toward the levers respectively. i

' 8. Apparatus of the class described having in combination a carbon pile, a plunger operating on the end of the pile, a lever operating on said plunger but being otherwise not connected therewith, an electro-magnet having an armature with apart bearing against said lever but being otherwise disengaged therefrom, resilient means acting to maintain said armature part in engagement with said lever and said lever in'engagement with said plunger, and resilient means pressing said plunger" toward said lever and away from said carbon pile.

9. Apparatus of the class descrihed having in combination, two'carbonpil'es connected in series with oneanoth'e'r, a lever operating on one'end of both piles to vary the resistance thereof, an electro-magnet having two po'le pieces, an armature therefor pivoted between said pole pieces, means whereby said armature gact-uates said lever, a coil controlling the energization of said magnet, a lever operating on the other end of said piles, another electro-magnet having two pole pieces, an armature therefor pivoted -between said last mentioned pole pieces and a coil controlling the energization of said last mentioned magnet to cause its armature to operate said second lever to vary the resistance of the pile independently of said first lever and electromagnet.

10. Apparatus of the class described having in combination a carbon pile, a lever operating on one end of the pile, a. potential 'eleetro-magnet having two pole pieces an armature therefor pivoted between said pole pieces and controlling the operation of said lever, a lever operating on the other end of said pile, a current electro-magnet having two polepieces and an armature therefor pivoted between said pole pieces and controlling the operation of said second lever, one of said magnets with its cooperating armature and lever acting to vary the resistance of the pile independently of the' "other magnet'and its cooperating armature and lever.

11. Apparatus of the class described having in combination, a carbon pile for regulating a generator field, a lever operating on --one endof the pile, -a potential elec'tro-magnet having'two pole'pieces, an armature therefor pivoted between said polepieces 'andeontrolling the operation on the other end 'ofsaidp'ile, a currentfelectro-rhagnet havin two 'pole pieces and an armature "there or pivoted between said pole pieces and controlling the operation of said second lever, one of said magnets with its cooperating a-r-In'a-t ur'e and {lever acting to vary the resistance of the pile independently of the other magnet and its cooperating armature and lever, 'a switclnand an armature affected by bothiof said-magnets for controlling the-operation of sa-id 'switch. 1-2.' Apparatus'of the class described havingiin combinatiom-a carbon pile, a lever operating on'one end of the pile, a potential "electro-magnet having two pole pieces an armature therefor pivoted between" said pole pieces and controllingLthe operation of said lever,'-'alever operating on the other end of said pile, a'currentelectro-magnet having twop'ole pieces' and an-ai'matu're therefor pivoted'bet-ween' said pole pieces and con- 'trolli ng'the'operation of said second lever, each of said magnets with its cooperating armature'a'nd lever acting to vary the resistance of the pile independently of the other magnet and its cooperating armature and lever.

13, Apparatus of the class described having in combination, a carbon pile, a lever operating on one end of the pile, a potential electro-magnet having two pole pieces an armature therefor pivoted between said pole pieces and controlling the operation of said lever, a lever operating on the other end of said pile, a current electro-magnet having two pole pieces and an armature therefor pivoted between said pole pieces and controlling the operation of said second lever, one of said magnets with its cooperating armature and lever acting to vary the resistance of the pile independently of the other magnet and its cooperating armature and lever and each of said armatures having damping bands on each side of its pivot.

14. Apparatus of the class described having in combination a carbon pile for regulating a generator, a potential magnet having two pole pieces and an armature pivoted between said pole pieces, means whereby said armature acts to vary the resistance of said pile, a spring opposing the action of the magnet on the armature, and means whereby the movement of the armature by the spring away from said poles is limited, said spring being so connected with the armature and adjusted that a predetermined magneto motive force applied to the potential magnet acts to substantially balance the spring throughout substantially the whole range of movement of the armature.

15. Apparatus of the class described having in combination a carbon pile for regulat ing a generator, an electro-magnet having two pole pieces and an armature pivoted between said pole pieces, means whereby said armature acts to vary the resistance of said pile, a spring opposing the action of the magnet on the armature, and means whereby the movement of the armature by the spring away from said poles is limited, said spring being so connected with the armature and adjusted that a predetermined magneto-motive force applied to the magnet acts to substantially balance the spring throughout substantially the whole range of movement of the armature.

16. Apparatus or" the class described having in combination a carbon pile for regulating a generator, a potential magnet having two pole pieces and an armature pivoted be tween said pole pieces, means whereby said armature acts to vary the resistance of said pile, a spring opposing the action of the magnet on the armature, and means whereby the movement of the armature by the spring away from said poles is limited, said spring being so connected with the armature and adjusted that a predetermined magnetomotive force applied to the potential magnet acts to substantially balance the spring throughout substantially the whole range of movement of the armature, but requiring a greater magneto motive force to move the armature in its initial movement toward the pole pieces.

17. Apparatus of the class described having in combination a carbon pile for regulating a generator, a potential magnet having two pole pieces, and an armature pivoted between said pole pieces means whereby said armature acts to vary the resistance of said pile, a spring opposing the action of the magnet on the armature, and means whereby the movement of the armature by the spring away from said poles is limited, said spring being so connected with the armature and adjusted that a predetermined magneto-motive force applied to the potential magnet acts to substantially balance the spring and any material back pressure of the carbon pile throughout substantially the whole range of movement of the armature,

18. Apparatus of the class described having in combination a carbon pile for regulating a generator, a potential magnet having two pole pieces and an armature pivoted between said pole pieces, means whereby said armature acts to vary the resistance of said pile, a spring opposing the action of the magnet on the armature, and means whereby the movement of the armature by the spring away from said poles is limited, said spring being so connected with the armature and adjusted that a predetermined magneto-motive force applied to the potential magnet acts to substantially balance the spring and the back pressure exerted by the carbon pile throughout substantially the whole range of movement of the armature, but requiring a greater magneto motive force to move the armature in its initial movement toward the pole pieces.

In testimony whereof I have signed my name to this specification.

ELI J. BLAKE. 

